| RGS5 — Regulator of G Protein Signaling 5 | |
|---|---|
| Symbol | RGS5 |
| Full Name | Regulator of G Protein Signaling 5 |
| Chromosome | 1q23.3 |
| NCBI Gene | 6053 |
| OMIM | 607073 |
| Ensembl | ENSG00000143248 |
| UniProt | Q9NZH6 |
| Diseases | [Hypertension](/diseases/hypertension), [Atherosclerosis](/diseases/atherosclerosis), [Stroke](/diseases/stroke), [Pulmonary Arterial Hypertension](/diseases/pulmonary-arterial-hypertension) |
| Expression | Vascular smooth muscle cells, [Pericytes](/entities/pericytes), Brain vasculature |
RGS5 (Regulator of G Protein Signaling 5) is a member of the RGS protein family with preferential expression in vascular smooth muscle cells and pericytes. RGS5 plays critical roles in regulating G protein-coupled receptor (GPCR) signaling in the cardiovascular system and has implications for cerebrovascular health and neurodegeneration.
RGS5 encodes a 177-amino acid protein containing a conserved RGS domain that functions as a GTPase-activating protein (GAP) for Gαq and Gαi subunits. Unlike many RGS proteins with broad tissue distribution, RGS5 exhibits remarkable specificity for vascular cells, making it a key regulator of vascular tone and blood flow.
RGS5 serves as a primary regulator of Gαq-mediated signaling in vascular smooth muscle cells. By accelerating GTP hydrolysis on Gαq subunits, RGS5 terminates signaling from vasoconstrictor receptors including angiotensin II (AT1R), endothelin-1 (ETA), and α1-adrenergic receptors. This termination prevents excessive vasoconstriction and maintains vascular homeostasis.
In the cerebral vasculature, RGS5 is highly expressed in pericytes, cells that regulate capillary blood flow and blood-brain barrier (BBB) integrity. RGS5 modulates pericyte contractility by controlling signaling from GPCRs that regulate pericyte tone, thereby influencing cerebral blood flow dynamics.
RGS5 expression in pericytes and endothelial cells contributes to BBB maintenance. Dysregulation of RGS5 may compromise BBB integrity, potentially allowing peripheral immune cell entry into the central nervous system—a hallmark of neuroinflammatory and neurodegenerative conditions.
RGS5 is a critical determinant of blood pressure regulation. Genetic variations in RGS5 are associated with hypertension susceptibility. RGS5 deficiency in mice results in heightened vascular responsiveness to vasoconstrictors and elevated blood pressure.
RGS5 plays protective roles in cerebrovascular function. Altered RGS5 expression is observed in stroke models, and RGS5 deficiency exacerbates ischemic brain injury through impaired vascular responses and increased inflammation.
RGS5 modulates vascular inflammation and remodeling in atherosclerosis. The protein influences smooth muscle cell proliferation and migration, key processes in atherosclerotic plaque development.
Given its role in pericyte function and BBB integrity, RGS5 has implications for various cerebrovascular disorders that contribute to vascular dementia and other neurodegenerative conditions.
RGS5 shows high expression in vascular smooth muscle cells throughout the body, with particular abundance in cerebral vasculature. In the brain, RGS5 is primarily localized to pericytes ensheathing capillaries and to vascular smooth muscle cells of larger cerebral arteries. Lower expression is detected in other cell types including macrophages and some neuronal populations.
RGS5 represents a therapeutic target for: